Homocysteine Analysis

Test Information

Elevations in plasma homocysteine levels may be associated with homocystinuria, cobalamin disorders, and vitamin B12 or folic acid deficiencies. Measurement of plasma homocysteine can be used to monitor patients undergoing treatment for Certain cobalamin disorders (CblC, CblD and CblE), which are characterized by hypotonia, failure to thrive, developmental delay and megaloblastic anemia and result in elevated homocysteine levels.

Turnaround Time

10 days

CPT Code(s)

83090

Cost

$100

Clinical Information

Homocysteine is a non-protein amino acid that is synthesized through the conversion of methionine. Elevations in plasma homocysteine levels may be associated with homocystinuria, cobalamin disorders (cblC, cblD, and cblE), and vitamin B12 or folic acid deficiencies.

Indications

The symptoms of homocystinuria include lens dislocation, osteoporosis, skeletal abnormalities such as genu valgum or a pectus deformity, thrombotic events, intellectual disability and psychiatric/behavioral disturbances. However, the phenotype is variable. Certain cobalamin disorders (CblC, CblD and CblE), which are characterized by hypotonia, failure to thrive, developmental delay and megaloblastic anemia, also result in elevated homocysteine levels. Measurement of plasma homocysteine can be used to monitor patients undergoing treatment for these conditions.

Methodology

Liquid chromatography-tandem mass spectrometry

Specimen Requirements

Plasma: at least 0.5 ml of plasma is required to perform this analysis. Peripheral blood should be collected in a sodium heparin tube. Plasma should be spun down, separated, and frozen within 4 hours of collection to prevent false elevations in homocysteine levels.

Transport Instructions

Plasma should be sent frozen, preferably on dry ice, via overnight delivery.

Have Questions Need Support?

Call our laboratory at 1-800-473-9411 or contact one of our Laboratory Genetic Counselors for assistance.
Robin Fletcher, MS, CGC
Kellie Walden, MS, CGC

Analyte Analysis, Analytes and Biomarkers, Biochemical Testing, Newborn Screening Follow-Up
Lucy's Story

Lucy's Story

When our daughter Lucy had a metabolic crisis at 7 days old, we were shocked and devastated to find out that she was born with a rare genetic disorder (MSUD). Her newborn screening results did not make it back in time to prevent the crisis, and no one at our local hospital was familiar with the disease. They did not know how to treat her. Calls were made to Greenwood Genetic Center to confirm her diagnosis...

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